nidui

A nidui is a type of ban, a basic type of ostracism that was used to distance a given individual from the community (more severe levels of excommunication include shamta and herem). The rules and regulations of nidui, including the requirement that someone in this state avoid contact with others as well as punishments that the person is supposed to accept upon himself, are delineated in the third chapter of Massekhet Moed Katan.